In recent years a substantial effort has been devoted to work involving the utilization of thermoplastic resins in fabricating fiber-reinforced composites. Investigations to date have verified that thermoplastic composites and adhesives have the potential of lowering processing costs and increasing the reliability of composite construction. The cost reductions are possible because faster and lower cost manufacturing procedures can be employed. However, because of the problems associated with linear polymeric systems, the use of thermoplastic resins as structural materials in aircraft applications has been limited.
Linear polymers have a very low solvent, creep and craze resistance. Solvents normally found around aircraft and air fields, such as hydraulic fluids, brake fluids, paint strippers, and the like, are potential hazards to such systems. It would, therefore, be highly desirable to have available a thermoplastic material which, when thermally treated, would become lightly crosslinked so as to obviate solvent induced problems inherent in linear polymeric material.
It is a principal object of this invention, therefore, to provide new and improved aromatic monomers which can be used in the preparation of thermally stable, high molecular weight polymers having the ability to react further after fabrication, thereby forming a lightly crosslinked, solvent resistant system.
Another object of the invention is to provide a process for synthesizing the aromatic monomers.
Other objects and advantages of the invention will become apparent to those skilled in the art upon consideration of the accompanying disclosure.